Handover Method in Mobile Network, Mobile Terminal and Mobile Network System Thereof

1. A method of performing handover in a mobile communication network, comprising: receiving a quality of service (QoS) requirement for each of a plurality of mobile services associated with a user terminal, the QoS requirement representing information about quality requested for a corresponding mobile service, wherein at least two of the plurality of mobile services have different QoS requirements; determining a suitable mobile network for each of the mobile services based on a corresponding QoS requirement to perform a handover operation for each mobile service; and requesting a handover operation of a first mobile service of the plurality of mobile services to a base station associated with a mobile network suitable for the first mobile service but not requesting a handover operation of a second mobile service of the plurality of mobile services to the base station based on the determination.

2. The method of claim 1 , wherein reception signal intensity of the connectable mobile networks is more than predefined threshold value.

3. The method of claim 1 , wherein the determining of one of mobile networks comprises determining a mobile network that provides quality most similar to QoS requested to a mobile network among mobile networks to which the user terminal can be connected as a network for handover.

4. The method of claim 1 , wherein the requesting of handover comprises transmitting bearer information and a quality profile that are currently set to the first mobile service to the base station.

5. The method of claim 1 , further comprising receiving first bearer information set to the base station from the base station in order to provide the first mobile service.

6. The method of claim 5 , further comprising transmitting the received first bearer information and second bearer information currently set to the first mobile service to the user terminal.

7. The method of claim 1 , further comprising releasing a bearer resource for providing the first mobile service after handover of the first mobile service is completed.

8. The method of claim 7 , further comprising transmitting buffered service data related to the first mobile service to the base station after handover to the base station is completed.

9. A mobile communication terminal comprising: a signal intensity detection unit configured to detect reception signal intensity of a plurality of mobile networks; a transmission unit configured to transmit a quality of service (QoS) requirement for each of a plurality of mobile services associated with the mobile communication terminal the QoS requirement indicating information about quality requested for a corresponding mobile service, wherein at least two of the plurality of mobile services have different QoS requirements; and a reception unit configured to receive an instruction for performing handover of a first mobile service to a base station but not handover a second mobile service among the plurality of mobile services to the base station, wherein a mobile network provided by the second base station is selected based on first QoS requirement of the first mobile service and second QoS requirement of the second mobile service.

10. The mobile communication terminal of claim 9 , wherein the reception signal intensity of the plurality of mobile networks or a quality requested to the plurality of mobile services is detected in every predetermined period.

11. The mobile communication terminal of claim 9 , wherein the reception unit receives bearer information set at the second base station from the first base station in order to provide the first mobile service.

12. The mobile communication terminal of claim 11 , further comprising a bearer setting unit that performs bearer setting for providing the first mobile service using the received bearer information.

13. The mobile communication terminal of claim 12 , wherein the bearer setting unit releases a currently configured bearer resource in order to provide the first mobile service after receiving bearer information from the first base station.

14. A mobile network system comprising: a reception unit configured to receive information about reception signal intensity of a plurality of mobile networks and a quality of service (QoS) requirement for each of a plurality of mobile services provided on a user terminal, the QoS requirement representing information about requested quality for a corresponding mobile service; a first handover determination unit configured to determine connectable mobile networks among the plurality of mobile networks using information about reception signal intensity; and a second handover determination unit configured to determine, for each of the plurality of mobile services, one of mobile networks to which the user terminal can be connected for handover using QoS requirement of each of the plurality of mobile services, wherein a first mobile service of the plurality of mobile services is handed over to a base station based on QoS requirement of the first mobile service but a second mobile service of the plurality of the mobile services is not handed over to the network based on QoS requirement of the second mobile service.

15. The mobile network system of claim 14 , further comprising a transmission unit that transmits bearer information and a quality profile that are currently set to the first mobile service among the plurality of mobile services to a base station for providing a mobile network determined as a network for handover.

16. The mobile network system of claim 15 , wherein the transmission unit transmits bearer information that is set to the base station to the user terminal in order to provide the first mobile service.